Thankfully, breast cancer has been becoming a lot less fatal over the past few decades, and scientists and medical doctors are continuing to make immense strides in understanding and treating it. Still, new research provides evidence that methods of screening and diagnosing the condition are permeated with racial biases that favor whiteness—similarly to mental health. Perhaps this is partially why black women are 40 percent more likely to die from breast cancer than white women, even though breast cancer is about equally prevalent among both races, the Centers for Disease Control and Prevention (CDC) reported.

A study recently published in JAMA Surgery outlines how traditional screening tools and guidelines do a disservice to women of color. The researchers examined nearly 748,000 women (aged 40 to 75) with breast cancer from 1973 to 2010 and found major differences regarding age at the time of diagnosis between races: 59 for white women, 56 for black women and Asian women, and 55 for Hispanic women. Additionally, a higher proportion of black and Hispanic women had more advanced breast cancer at the time of diagnosis than white and Asian women.

Though women of color were diagnosed with breast cancer at a younger age than white women, the age at which most health agencies recommend regular mammogram screenings is based on research done on white women.

Here’s where the racial bias comes in: Though women of color were diagnosed with breast cancer at a younger age than white women, the age at which most health agencies recommend regular mammogram screenings is based on research done on white women. The US Preventive Services Task Force doesn’t recommend mammogram screenings every other year for women until they hit age 50, but the study found that regular screenings should begin at age 47 for black and Asian women and 46 for Hispanic women.

Speaking to Tonic, David Chang, MD, study co-author and associate professor of surgery at Massachusetts General Hospital, said, “This is one example of a larger problem. Most research is done in mostly white populations.”

“Flawed science can harm more people than flawed clinical care, which is why it is so important to detect and eventually eliminate these sorts of hidden biases in the scientific literature.” —Dr. David Chang, study co-author

In a press release, Dr. Chang outlined how these biases (such as testing only on male animals) are affecting science, medicine and, ultimately, women’s health. “Flawed science can harm more people than flawed clinical care, which is why it is so important to detect and eventually eliminate these sorts of hidden biases in the scientific literature,” he said.